Not Applicable
Not Applicable
1. Field of the Invention
The present invention relates to equipment for dispensing a carbonated beverage into an open container from which the beverage will be consumed; and more particularly to such equipment in which the dispensing occurs in a manner that minimizes foaming of the beverage.
2. Description of the Related Art
It is common for carbonated beverages, such as soda and beer, to be supplied in a sealed canister or keg that then is connected to a tap at an establishment, at which the beverage is to be served. As used herein the term xe2x80x9cestablishmentxe2x80x9d includes businesses, residences and other facilities at which a carbonated beverage is served. Pressurized gas, such as carbon dioxide, is injected into the keg to force the liquid beverage through an outlet tube to the tap from which it is dispensed into serving containers of various sizes.
The carbonated beverage usually foams upon entering the serving container. As a consequence, personnel operating the tap typically fill the serving container until the level of foam reaches the brim and then wait for the foam to settle before adding additional beverage. In some instances several iterations of this process are required before the container is filled with liquid to the proper serving level. Such xe2x80x9ctopping offxe2x80x9d necessitated by the foaming of the beverage prolongs the dispensing operation and impedes the ability to fully automate carbonated beverage dispensing.
Automated dispensing is particularly useful in establishments where large volumes of beverages are served, such as sports arenas and stadiums. It is desirable at such facilities to fill each container to the full serving level as fast as possible with minimal waste.
U.S. Pat. No. 5,603,363 describes a dispensing system which satisfies that desire. In that system, the carbonated beverage is fed into an elevated tank which is open to the atmosphere so that the beverage stored therein is at atmospheric pressure at all times. A spout is located beneath the tank and has a valve through which the beverage flows into a serving container. Selective operation of the valve and movement of the serving container enable rapid dispensing with minimal foaming. As a result of the tank being open to the atmosphere, the beverage tends to degas upon prolonged storage in the tank. In addition, there is a concern that bacteria and other substances may enter the open tank and contaminate the beverage therein, especially between hours of operation of the beverage establishment.
Alternative systems, such as described in U.S. Pat. No. 3,881,636, employ a closed tank with a vent tube at the top of the tank that provides a restricted passage to the atmosphere. The beverage is fed to the tank under the same pressure as in the keg and is maintained substantially at that elevated pressure until a spout is opened to fill a glass. At that time the tank pressure is reduced to the atmospheric level before the valve on the spout is opened. In a high volume dispensing establishment, this latter type of dispensing system has the disadvantage that time is lost while the reservoir is brought down to atmospheric pressure before the spout is opened. A further delay results from having to raise the tank to the keg pressure in order replenish the beverage in the tank. Thus it is desirable to increase the speed of dispensing further. In addition, this latter system has a small orifice through which the tank always is open to the atmosphere. Thus contaminants may enter this tank during prolonged periods of non-use.
To dispense a carbonated beverage into a serving container, a reservoir of a dispenser is connected to a source which supplies the carbonated beverage at a first pressure level that is greater than atmospheric pressure. A quantity of the carbonated beverage is held in the reservoir at a second pressure level that is less than the first pressure level and substantially greater than atmospheric pressure. This intermediate second pressure level inhibits gas from escaping from the beverage so that the carbonation is maintained.
When it is desired to dispense the carbonated beverage into the serving container, a vent passage between the reservoir and an ambient environment is opened to lower pressure in the reservoir to substantially atmospheric pressure. After the reservoir is at substantially atmospheric pressure, another passage in opened through which the beverage flows from the reservoir into the serving container. Foaming that often occurs as a carbonated beverage flows into a serving container is minimized by reducing the reservoir pressure to substantially atmospheric pressure.
In the preferred embodiment of the dispensing method, the amount of carbonated beverage contained in the reservoir is sensed. When less than a first amount of carbonated beverage is in the reservoir, carbonated beverage is transferred from the source into the reservoir. Thereafter, when carbonated beverage in the reservoir reaches a second amount, the vent passage is closed. The transfer of the carbonated beverage is terminated a predefined period of time after closing the vent passage, wherein the quantity of the beverage that enters the reservoir during that predefined period of time causes the pressure to increase to the second pressure level.